Getting Started
Irregular income needs a different contribution rule
Fixed monthly contributions assume a fixed monthly income, and people paid irregularly need a rule expressed as a proportion of receipts rather than as an amount.
Contribution advice is written for salaried people with predictable pay dates. Self-employed and commission-based earners face a different problem, and a fixed monthly figure is the wrong instrument for it.
Why a fixed amount fails on variable income
A monthly figure has to be sized against the worst month, otherwise it fails in that month. Sized that way, it captures very little in the good months that make up the difference.
The alternative is sizing it against average income, which produces failed payments and overdrafts in thin periods. Both errors push people towards contributing nothing rather than towards contributing something.
The underlying mismatch is that the obligation is fixed while the resource is variable. Rules that fail on variable inputs tend to be abandoned rather than adjusted.
A proportion of receipts adapts automatically
Expressing the contribution as a share of each payment received removes the mismatch. A quiet month produces a small contribution and a busy month a larger one, without any decision.
The share is chosen once, against what is affordable across a full year rather than against any single month. Once chosen, applying it is arithmetic rather than judgement.
The habit is then attached to the event of being paid rather than to a calendar date. For irregular earners the payment event is the reliable trigger, and the calendar is not.
A separate holding account absorbs the timing
Money moved on receipt often needs to sit somewhere before it is invested, particularly where the earner also has to reserve for taxes and irregular business costs.
Using a separate account for that reserve keeps it out of the balance that gets spent. What is visible in the main account is then genuinely available, which restores the usefulness of that number.
Tax obligations for self-employed people vary by jurisdiction and change, and the amounts and timing are matters for a professional rather than a rule of thumb.
The floor and the ceiling both need defining
A proportional rule can produce contributions too small to be worth processing, and some providers apply minimums. Setting a floor below which the money simply accumulates avoids fragmenting it.
A ceiling matters for a different reason. Exceptionally good months tempt a proportional rule into moving sums that were actually needed for the following quarter's costs.
Defining both in advance means the rule can be followed mechanically. A rule requiring interpretation on each payment is a decision in disguise, and decisions are what the habit exists to avoid.
Reviewing the share rather than the amounts
Annual review for a variable earner is about the percentage, not the contributions. The contributions are outputs; the share is the only setting that was actually chosen.
If a year of receipts shows the share was comfortable throughout, it can be raised. If it forced borrowing in quiet months, it was too high regardless of what the total came to.
Judging the rule by the total invested confuses the outcome with the setting. A good year can flatter a share that was unsustainable, and a poor year can condemn one that was not.
Questions readers ask
Should I automate into a workplace scheme or my own account?
Where an employer matches contributions, that match is normally considered first because it is an immediate uplift, but scheme rules and tax treatment vary widely by country.
Does automating remove all judgement?
It removes the monthly judgement, which is the one made worst. Annual judgements about amount and structure remain, and those are the ones worth keeping.
